1. Field of the Invention
The present invention relates to a vacuum film forming/processing apparatus and method for performing a film process such as forming various thin films onto a substrate or etching films, in vacuum atmosphere.
2. Description of the Related Art
In manufacturing processes of thin film applied devices such as a thin film magnetic head for a magnetic recording apparatus and various semiconductor devices, a film forming apparatus using a dry process such as a sputtering apparatus is often used. A film forming apparatus of such a kind is disclosed in, for example, Japanese Publication of Unexamined Patent Application No. 2-282474. The film forming apparatus disclosed in the publication is constructed as a sputtering film forming apparatus and comprises a conveying chamber having a conveying apparatus in addition to an introducing chamber, a wafer cleaning chamber, and a film forming chamber.
In the example of the film forming apparatus, one etching chamber as a wafer cleaning chamber and one film forming chamber are provided. Generally, a plurality of film forming chambers and a plurality of etching chambers are often provided in accordance with the kinds of thin films to be formed. The film forming chamber is used for performing a thin film forming process onto a substrate as an object on which thin films are formed. The etching chamber is generally used to clean a substrate (wafer) and perform an etching process to the formed thin film. The introducing chamber is used to introduce a substrate and a target from the atmosphere into the apparatus.
In the film forming apparatus, processes of forming and etching a thin film and the like (hereinafter, generically called a film forming process) are performed while sequentially conveying the substrate into a corresponding film forming chamber or etching chamber in accordance with each process. The conveyance of the substrate is carried out by the conveying apparatus in the conveying chamber. The introducing chamber is switched between an atmospheric pressure state and a vacuum state every introduction (replacement) of a new group of substrates and the conveying chamber is always maintained under a vacuum state.
As mentioned above, in a conventional film forming apparatus, a substrate is conveyed to the film forming chamber or the etching chamber always via the conveying chamber. There are consequently problems such that dusts and contamination, which occur in association with movement of the conveying apparatus in the conveying chamber, adhere to the substrate, so that an adverse influence is exerted on the film quality or the uniformity (stability) of the film quality deteriorates.
Although the conveying chamber is maintained under a vacuum state in the film forming apparatus, it is difficult to reduce the volume of the conveying chamber, since it has the conveying apparatus therein. Further, it is also difficult to reduce the volume of the film forming chamber, since it has all of members and mechanisms necessary for film formation, that is, both a part related to the substrate and a part related to the target. Therefore, in case of putting the conveying chamber back under the atmospheric pressure for maintenance or the like of the conveying chamber, or putting the film forming chamber back under the atmospheric pressure for replacement or the like of a target, it takes long time to open the chamber to the atmosphere and exhaust the air. In order to shorten the time, a vacuum pump having a high exhaust capability is necessary and the cost increases.